An electrical panel or panelboard, has a main bus and individual connection points on the bus that are connectable to electrical devices, such as circuit breakers for branch conductors and any other electrical devices designed to be installed for a branch circuit. Because the circuit breakers, sometimes referred to herein simply as “breakers” for convenience, and other branch electrical devices are typically mounted directly to the panelboard, an operator and/or tools may come in contact with exposed conductors in the panelboard when installing or removing the circuit breakers from the panelboard. Thus, it is recommended that power be shut off to the panelboard as a precaution when electrical devices are being installed or removed. However, it may be considered desirable in some cases to keep the panelboard energized to prevent an electrical hazard as a consequence of deenergization, or operators may intentionally keep the power on in the interest of saving time. Moreover, shutting off power to the panelboard can be a major inconvenience, especially for data centers, hospitals, and other critical applications that require a high availability power source.
A need exists for an improved way to safely insert and remove a circuit breaker or other switching equipment from an electrical panel as part of a larger scheme for installing and removing branch circuit devices without deenergizing the electrical panel. Measures to prevent unintentional contact with live, i.e. energized, conductors are often known as “finger safe” provisions. Work on energized equipment will be known herein as “live work”. Particular panelboards, oftentimes called load centers, are front-accessible, wall-mounted panelboards, and typically for low voltage light, heat or power circuits in residential applications, which have miniature circuit breakers to define and protect each branch circuit. Due to their size, design, and economic constraints, load center-type panelboards can present unique challenges for the above considerations. Further, it is desirable that production and installation of panelboards be made economical, flexible and simple wherever possible while their use and operation remain as safe as possible.